The nadir platelet count in the first 48 h after ICU admission is a potential predictor of acute kidney injury in hemorrhagic shock patients.

Background: The relationship between the nadir platelet count within the first 48 h after intensive care unit (ICU) admission and the occurrence of acute kidney injury (AKI) in hemorrhagic shock patients remains unclear. This study investigated this association in adult patients admitted to the surgical ICU for hemorrhagic shock.

Methods: We included 124 hemorrhagic shock patients, excluding those with pre-existing AKI or chronic kidney disease (CKD), admitted to two affiliated hospitals between January 2019 and May 2022. The nadir platelet count was defined as the lowest value within the first 48 h after ICU admission. AKI was diagnosed based on Kidney Disease Improving Global Outcomes (KDIGO) criteria. We used multivariate logistic regression to identify independent risk factors for AKI and analyzed the area under the receiver operating characteristic curve (AUC) for diagnostic accuracy.

Results: Patients with AKI (n = 72) had significantly lower nadir platelet counts compared to those without AKI. The nadir platelet count was identified as an independent risk factor for AKI (OR = 0.988, 95% CI: 0.978-0.999, P = 0.035). The AUC for predicting AKI was 0.862 (95% CI: 0.795-0.929). Combining the nadir platelet count with serum cystatin C levels enhanced the predictive accuracy (AUC = 0.922, 95% CI: 0.870-0.973, P < 0.001).

Conclusions: The nadir platelet count in the first 48 h after ICU admission is independently associated with the risk of AKI in hemorrhagic shock patients and could serve as a potential predictor when combined with serum cystatin C levels.